The interior roof of motor vehicles is commonly outfitted with a vehicle headliner. The vehicle headliner provides several benefits. For example, the headliner provides thermal insulation to help keep the vehicle interior at a comfortable temperature. The headliner also provides acoustical dampening to reduce the level of noise inside the passenger compartment for the vehicle. The headliner also provides a decorative finish to the interior of the vehicle roof.
Additional structures are often positioned between the vehicle headliner and the roof of the vehicle. These additional structures provide a head impact countermeasure (HIC) to reduce the risk of head injury in the event of an accident. The HIC is generally formed of a plastic and positioned between the headliner and the vehicle roof and operates by deforming under the impact force of a vehicle occupant's head. During deformation, the HIC dissipates crash energy and thereby provides a degree of protection to the vehicle occupant.
The HIC structures are commonly positioned between the headliner and the vehicle roof by one or more methods known in the art. These methods include adhering the HIC structure to the headliner and fastening it to the vehicle roof and peripheral structure. Regardless of the method used to position the HIC structure, an undesirable assembly step is introduced to the manufacture of the vehicle or its headliner. Also, undesirable tooling expenses are incurred in creating the requisite molds or other devices used to form and assemble the HIC structures separately from the headliner.
It is also desirable to improve the recyclability of vehicle headliners. Presently, vehicle headliners are formed from several layers of materials. One of these materials is glass mat or fiberglass. Other adhesives and cross-linked resins such as polyol and isocyanate are also used to secure the layers to each other. These materials, adhesives and resins make recycling vehicle headliners less than desirable since they are difficult, if not impossible, to remove from the headliner prior to recycling. However, when left in, these materials reduce the usefulness of the resultant recycled material.